Express your answer as a mixed number simplified to lowest terms. $3\dfrac{2}{6}+15\dfrac{1}{6} = {?}$
Explanation: Separate the whole numbers from the fractional parts: $= {3} + {\dfrac{2}{6}} + {15} + {\dfrac{1}{6}}$ Bring the whole numbers together and the fractions together: $= {3} + {15} + {\dfrac{2}{6}} + {\dfrac{1}{6}}$ Add the whole numbers: $=18 + {\dfrac{2}{6}} + {\dfrac{1}{6}}$ Add the fractions: $= 18+\dfrac{3}{6}$ Combine the whole and fractional parts into a mixed number: $= 18\dfrac{3}{6}$